1. Field of the Invention
The present invention relates to a mixing valve controlled with one lever, a valve in which the total quantity and mixing ratio of cold and hot water are regulated by means of one lever and the inlets for cold and hot water are formed by two ceramic plates of which one is fixed to the valve body and the other is movable by means of the lever.
2. Description of the Prior Art
Valves of this type have been described in, for example, U.S. Pat. Nos. 3,661,180 and 3,533,436. In these valves there is on top of the ceramic plate a plastic part which protects the ceramic valve plate from wear and is held in place by the pressure of the spherical part of the control lever. The plastic part also serves as a slide plate whcn the valve is regulated. The plate is not sealed and does not form water channels.
Furthermore, from U.S. Pat. No. 3,384,119 a mixing valve is known having parallel through-flow openings for cold and hot water in the valve piece movable against the valve seat. This valve, however, deviates from the former ones in that two ceramic plates are not used. The flow channels end in the side edge of the valve piece and are situated asymmetrically in relation to the fixed discharge opening therebelow, except when the mixing ratio is 1:1. This is one disadvantage when considering the operation of the valve.
Valve structures using two ceramic plates have also been introduced in U.S. Pat. Nos. 3,476,149 and 3,433,264 and in the published German Patent Application 2 230 174.
A ceramic valve construction has an advantage in that the plates can be clapped together tightly so that no rubber gasket or other seal is necessary. This results in that the life of the valve is very long and its need for maintenance very small.